Queries do not fallback to unauthorized user role if custom defined auth cookie header is not present

### Version Information

Server Version: v2.0.8.cloud-3

### Environment

Cloud

### What is the expected behaviour?

If a cookie header is identified in HASURA_GRAPHQL_JWT_SECRET, but not provided in a request, it should assume any anonymous defined role.

### Keywords
header, cookie, jwt

### What is the current behaviour?

Server error that the cookie was not found.

### How to reproduce the issue?

1. Define `HASURA_GRAPHQL_JWT_SECRET` with an optional header type of cookie and a custom name.
2. Define an anonymous role
3. Make a query without. the specified cookie.

### Screenshots or Screencast

### Please provide any traces or logs that could help here.

### Any possible solutions?

### Can you identify the location in the source code where the problem exists?

### If the bug is confirmed, would you be willing to submit a PR?

Start by reproducing the request described with a custom cookie header in HASURA_GRAPHQL_JWT_SECRET, an anonymous role, and no cookie. Trace the JWT authentication handling to find why a missing cookie is treated as an error; done means the request falls back to the configured anonymous role without that error, with regression coverage for the scenario.

Written by the indexing model from the issue text.